20-21

GNFAC Avalanche Forecast for Sat Feb 13, 2021

Snowpack and Avalanche Discussion

<p>A dusting of snow overnight doesn’t change the big picture avalanche situation. We’re now five days out from the end of the largest storm of the season. 2-4 ft of snow fell during that storm and there were widespread natural avalanches (see the <a href="https://www.mtavalanche.com/avalanche-activity"><u>Avalanche Log</u></a> for a full list). The snowpack is slowly stabilizing, but the weak snow low in the snowpack remains concerning.&nbsp;</p>

<p>On Thursday, snowmobilers triggered large avalanches in the Lionhead area and near Big Sky (<a href="https://www.mtavalanche.com/images/21/lionhead-snowmobile-triggered-sli… photo</u></strong></a>, <a href="https://www.mtavalanche.com/images/21/remotely-triggered-slide-portal-1… Creek photo</u></strong></a>). The slides near Big Sky were triggered from a slightly less steep slope in between the two slopes that slid. Triggering similar large avalanches remains possible today. Avoiding steep slopes is the simplest and the safest plan. If you are going to get into avalanche terrain, make sure you’re carrying rescue gear (beacon, shovel, and probe), ride one at a time and have a partner watching you from a safe spot so they’re ready if something goes wrong. Snowpack tests can be a good double check before committing to a slope, but don’t let “stable” snowpack test results lull you into a false sense of complacency (<a href="https://www.youtube.com/watch?v=Zyj4LwxoEaU"><strong><u>Teepee Basin video</u></strong></a>).&nbsp;</p>

<p>With human triggered avalanches possible today, the avalanche danger is MODERATE.</p>

<p>&nbsp;</p>

<p>Large avalanches during last weekend’s big storm in Cooke City should continue to give you pause today. Three to 4 ft of new snow and strong winds led to a large avalanche on the south face of Mt. Abundance (<a href="https://www.mtavalanche.com/images/21/large-avalanche-mt-abundance"><st…;), a slide on Town Hill (<a href="https://www.mtavalanche.com/images/21/natural-avalanche-town-hill-cooke…;), and slides that propagated widely, low on Woody Ridge (<a href="https://www.mtavalanche.com/images/21/woody-ridge-avalanche-wide"><stro…;). These slides broke on weak snow low in the snowpack. It will take hitting just the wrong spot to trigger an avalanche on these layers. Don’t let tracks on a slope fool you. Make good decisions for yourself, because it may be the 10th or 50th rider that triggers the whole slope. The avalanche danger today is rated MODERATE.&nbsp;</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

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Upcoming Avalanche Education and Events

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:

Natural avalanche in Beehive Basin

Beehive Basin
Northern Madison
Code
SS-N-R2-D2
Latitude
45.34070
Longitude
-111.39100
Notes

Natural avalanche on an east aspect in Beehive Basin. Likely broke during the avalanche warning on 2/7/2021. Appears to have broken ~4ft deep on weak snow near the ground.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Snowmobile Triggered Slide on Lionhead Ridge

Lionhead Ridge
Lionhead Range
Code
SS-AMu-R3-D2-O
Elevation
9500
Aspect
NE
Latitude
44.71450
Longitude
-111.31800
Notes

Snowmobile triggered slide on Lionhead Ridge in Upper Watkins drainage on 2/11/2021. Appears to have broken on weak snow near the ground. 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
3
D size
2
Bed Surface
O - Old snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural Avalanche on Lionhead Ridge

Watkins Creek
Lionhead Range
Code
SS-N-R3-D2
Latitude
44.75360
Longitude
-111.33000
Notes

Natural avalanche on Lionhead Ridge in upper Watkins Creek. Likely broke on Sunday 2/7. Appears to have failed on weak snow near the ground.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
3
D size
2
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year